Glee Sneak Peek: The Cast Performs "Rockin' Around the Christmas Tree" and It's Adorable—Watch Now

Exclusive! In a clip from tonight's episode of the Fox hit series, New Directions performs a classic Christmas tune for "Previously Unaired Christmas"

Glee is ready to rock around the Christmas tree. Literally.

The Fox hit's annual Christmas episode airs tonight and as an early present, we're gifting you with an exclusive sneak peek at "Previously Unaired Christmas." (You're welcome, and we're sure our gift is already in the mail, yes?)

In this clip from the festive outing, New Directions, along with Will (Matthew Morrison), take on Brenda Lee's "Rockin' Around the Christmas Tree," one of the most iconic Christmas songs of all-time.

Spoiler alert: you won't be able to keep a smile off your face while watching their performance!

Um, raise your hand if you want to join right in with the gang and sing "Rockin' Around the Christmas Tree" while decorating a tree together?!

But New Directions isn't decorating the tree they're also rockin' around just for the fun of it as the school is holding its 50th Annual Christmas Tree Decorating Contest. This year's theme? "Green is Good!" (So maybe the McKinley stoners, who have a cannabis Christmas tree, have a slight edge?!)

In a fun twist, Sue Sylvester (Jane Lynch) introduces tonight's episode as a Christmas special that Fox didn't allow to air from last year as it was deemed too offensive and racy. And while the New Directions members are busy auditioning for roles in McKinley High's living Nativity Scene, Rachel (Lea Michele), Kurt (Chris Colfer) and Santana (Naya Rivera), who visits the duo for the holidays after her breakup with Brittany (Heather Morris), are hard at work as Santa's elves in a New York City mall.

And creator Ryan Murphy has been doling out early Christmas gifts to fans on Twitter as well, revealing all of the cast members set to return for the show's highly anticipated 100th episode.

Not only will Mark Saling, Amber Riley and Harry Shum Jr. be returning, Murphy also revealed that Heather Morris, who left the show to give birth and be a mom at the end of last season, will be back. Plus, beloved guest star Kristin Chenoweth will also be stopping by! Oh, and it was just announced today that fan favorite Dianna Agron will be making her first appearance on the series since Will and Emma's (Jayma Mays) wedding in season four. Huzzah!

Fans can expect to see all of the original cast members perform, with a source telling us, "Most of the songs will be sung by the Originals, with special guest stars as well. The Old New Directions."